1. Field of the Invention
This application is a U.S. National Stage Application based on International Application Number PCT/KR2013/002913 filed on Apr. 8, 2013, which claims priority to Korean Application Number 10-2012-0035930 filed on Apr. 6, 2012. Both applications are incorporated herein in their entirety by this reference.
The present invention relates to a gate valve, and in particular to a gate valve 100 which comprises a valve blade 120 which comes into close contact with a valve seat 111 formed around an opening 112 in a valve housing 110 and is configured to close the opening 112 from inside; a valve rod 130 which is connected to the valve blade 120 and sealingly protrudes by way of a bellows 131 from the inside of the valve housing 110 to the outside and which moves in an upward and downward direction and moves in a horizontal direction; a guide housing 140 which is connected to an outer side of the valve housing 110; an L-motion block 150 which is installed in the interior of the guide housing 140 and is engaged and connected to the valve rod 130, with a guide roller 151 being installed at both sides of the L-motion block 150; a cam block 160 which is installed in the interior of the guide housing 140 and includes a valve rod pass hole 161 through which the valve rod 130 passes and a slanted groove 162 which is formed at both sides and is obliquely formed in a closing direction “C” in a downward direction, with the guide roller 151 being inserted in and guided by the cam block 160; a driving rod engaging roller 172 which is installed at an lower end of the valve rod 130; a driving rod 170 in which the driving rod engaging roller 172 is inserted and guided and which has a driving rod slanted groove 171 obliquely formed in a closing direction “C” in a downward direction and is engaged to the cam block 160; an elasticity providing unit 175 which is configured to provide elasticity between the L-motion block 150 and the driving rod 170; and an upward and downward driving unit 180 which drives upward and downward the driving rod 170.
2. Prior Art
The present invention is directed to a gate valve which is configured to open or close a transfer passage though which an IC (Integrated Circuit) or processed things such as the parts of the IC are transferred from a vacuum process chamber to another vacuum process chamber or is configured to open or close a flow passage of a fluid such as compressed fluid, gas, etc. or an exhaust flow passage.
In an apparatus for processing a semiconductor wafer or a liquid crystal substrate, the semiconductor wafer or the liquid crystal substrate is inserted or withdrawn from a variety of process chambers by way of a communication passageway. A gate valve is typically installed in the communication passageway in order to open or close it.
As an example of the gate valve, many kinds of gate valves are disclosed. As a representative example of such a gate valve, there is the Korean patent registration number 10-0338163 of the patent document 1 (title of the invention “gate valve”).
The gate valve of the above-mentioned patent document 1 is characterized in that a valve desk in a valve box is configured to freely move toward a portion where separates from or comes into close contact with a valve seat through a valve rod which sealingly protrudes from the valve box by means of an operation unit installed in the valve box. The gate valve allows the valve desk to be pressed against the valve seat in the valve box since the valve rod obliquely moves when the movement of the valve rod is almost finished. The operation unit may be configured to connect the piston rod and the valve rod of the piston-cylinder apparatus with the aid of the roller and the slanted, longitudinal hole which is configured to guide the roller or may be configured to connect the ends of them with the aid of a slanted link which freely pivots the rotations.
As illustrated in FIG. 1a, the related gate valve is characterized in that the valve desk operates along a predetermined operation passageway which is slightly slanted with respect to upward and downward directions and a horizontal direction, so there may be any interferences with a variety of components installed in the interior of the gate valve or impurities produced due to mechanical abrasions may input in the process chamber.
In order to improve the construction of the gate valve which has a slanted, operative passageway, as illustrated in FIG. 1b, there is proposed a construction like the Korean patent registration number 10-2011-0073476 (title of the invention “vacuum valve”) of the patent document 2 which allows the valve desk to move in a horizontal direction toward the closing position after it is first driven in an upward direction.
The vacuum valve of the patent document 2 comprises a wall with a valve opening surrounded by a valve seat; at least one valve plate which is arranged in a vacuum region of the vacuum valve (here, the valve plate may be moved from an opening position to an intermediate position in a vertical direction, and it may be moved to from its intermediate position to a closing position in a horizontal direction which is vertical with respect to the vertical direction); at least one valve rod which has a valve plate (the valve rod may be guided out of the vacuum region of the vacuum valve and may move in a vertical direction or a horizontal direction wherein the vertical direction is in parallel with respect to the vertical coordinate of the valve rod); and a vertical drive apparatus and a horizontal drive apparatus which are arranged outside the vacuum region of the vacuum valve (the valve rod may be moved in a vertical direction or a horizontal direction by means of the above apparatuses so as to move the valve plate).
The vacuum valve of the patent document 2 is very efficient in its operative passageway; however for the sake of such an operation, it requires a vertical drive apparatus and a horizontal drive apparatus, and its construction is complicated, and manufacture cost is high. For the sake of accurate opening and closing operations, the vertical drive apparatus and the horizontal drive apparatus should cooperate and operate on accurate timing in set operation sequence. For this cooperation, more complicated elements are necessary.